Effect of Modern Methods of Construction Research Paper

Introduction

Modern method of construction is a technology involving various forms supply chains, specification, prefabrication and off-site assembly. MMC includes;

• Make use of more effective material
• Speed up hiring delivery
• Enable high standards of design quality
• Can help to reduce resource consumption

It has often been regarded as a mean of improving quality, reducing time spend on site, improving on site safety and over coming sill shortages in the construction oh hose holds.

History of Construction in the United Kingdom

In total about one million houses were built during the 20^{th C} many of which were designed to be temporary. However problem arose over the quality of building materials and poor workmanship leading to negative attitude towards prefabrication.

This has however continued to be used in the U.K especially in hospitals, hotels and schools as well as housing in other countries.

Emergency of modern methods of construction

This primarily involves the manufacturing of homes in factories with potent benefits such as faster construction, fewer housing defects and reduction in energy use and waste.

MMC is a new term intended to reflect technical improvement in fabricated, encompassing of on and off site construction methods.

What are the modern forms of construction?

It involves the manufacturing of house parts off site in a specially designed factory. The main two products of MMC are;

• Panels; this include ready made walls, floors and floors. This are transported to the site and are assembled quickly often within 34 hours. Some panels have writing and plumbing already inside them making construction faster.
• Modules; this include ready made rooms which can be pieced together to make s whole house of flat but are frequently used for bathrooms and kitchens where all the fittings are added in the factory and it is also known as ‘pods’.

MMC can also include innovative site methods an example being use of concrete moulds, a range of material is used for MMC and the most common one being wood, steel and concrete. Although most houses in the U.K. have adopted the MMC the have brick outer layer and it is not easy to notice them.

The main advantage of using MMC is that;

• MMC houses have typically fewer defects and are built more quickly and are quite reliable.
• MMC houses can be more efficient, may involve less transportation of materials and produce less waste.
• Their may be fewer accidents and less impact on local resident during construction.

Current use of MMC

Majority of homes in the U.K are still under the old form of ‘bricks and blocks’ masonry. However within the last few years their has been increased use of MMC for housing driven by arrange of factories including demand for faster construction and skill shortage.

Many large private investors have recently invested in MMC thus although there is uncertainty about the amount the MMC housing production will increase.

In the U.K it has been estimated that the national house building council has built 10% are built with timber frames, and 5% using MMC this is equivalent to about 25000 MMC homes per year.

MMC internationally

In Japan about 40% of the new houses are MMC, in other European countries there is greater use of MMC houses especially in the Scandinavian countries and Germany. Some house building companies in Europe have started exporting their houses to the U.K. an example is one U.K housing association is exporting modules from Poland.

Although there are no certain reason for greater use of MMC houses suggestion may include;

• In cold climates the building season is short due to the extreme bad weather but use of MMC allows quick construction.
• MMC building materials like timber are more available than the brick and block.
• There is a greater tradition of self built housing. MMC way of construction appeals because faster construction reduces disruption to neighbours and allow earlier occupancies.
• There are certain preferences for certain house styles e.g. timber frame Scandinavian.

MMC Policies

The government has come to believe that MMC has social, economical and most importantly environmental benefits and thus has established initiative to encourage its use focusing on the social housing sector. From 2004 the housing corporation, the social housing regulatory for England and Wales embarked on building of new houses which were all built on the MMC equivalent.

The millennium communities overseen by the generation agency English partnerships are also using MMC. There is an agreement between the housing corporation and the English partnership to built 1300 key houses for workers using MMC.

Although the government has little influence on the private sector on construction, it has with industry sponsored rethinking construction programmes and encouraging use of MMC.

Issues

Despite the fact that the government is keen on encouraging the use of MMC for building, research is still on going to assess its benefit. Issues also arise on cost of MMC, industry capacity, its environmental benefit, the quality of such housing, public acceptance, planning and building regulations. I shall discuss each one of them individually;

Cost

Although most house builders argue that MMC is less expensive than the traditional methods, industry resource indicates increased cost of about 7-10%. The reason for higher cost may be difficult to discern because most project financial information is confidential, and traditional masonry building costs vary widely too.

It may be that the high cost can be attributed to some of the benefits of using MMC such as better quality houses and fewer accidents, which are not obviously reflected in the project account.

MMC housing is faster to build, which reduces on site construction time by 50% and thus reducing labour costs. Quicker construction is an extra benefit to the builders of apartments because viewing only starts once all flats are furnished and for housing associations who will start receiving rent earlier. This however is less important to private house builders as they rarely sell all the property on a new development at once.

Industry Capacity

Industry capacity can be a barrier to increasing the number of houses build using MMC. This can fall in two categories;

• shortage of skills
• the factory capacity to manufacture parts

Skills

When it comes to the U.K there is a shortage of skilled labour, to about 80% of house builders have reported difficulties with recruitment. When using MMC the build house parts in factories and faster on site thus fewer construction labourers are required.

Although there are uncertainty about the level of skills needed for MMC compared with masonry construction, MMC can require high skilled labour for precise on site assembly of factory made house parts. Some of the problems with pre-fabricated housed build during the 20^th c stemmed form poor skills, rather than defects with the housing materials.

The construction industry training board , funded by the government is developing MMC training courses for the estimate 2000 workers erecting MMC housing with no formal qualification.

Factories

Currently in U.K there are over 30 houses building factories. Their capacity can estimate to produce about 30000 MMC houses per year. Production could be increased by implementing more factory shifts.

Environmental Benefits

The government is promoting the environmental benefits of MMC as are many of the manufacturers. Research conducted by the building research establishment found MMC homes to be more energy efficient, but their has been no sufficient evidence of waste and transport reductions. Evaluating environmental benefit of MMC housing development is complex because it is difficult to attribute outcome solely to the use of MMC.

Energy Saving

Houses build using MMC typically require less energy to heat because of increased level of insulation fitted in the walls and roofs and also less air leakage from the building.

Among the reasons house builders are interested in MMC is because they anticipate that the energy required of the U.K regulation will soon become more stringent.

Waste

In the U.K construction and demolition waste comprises of 25%. The amount of waste produced using MMC is likely to be reduced because factory materials can be ordered to the exact specifications, and there is a lower risk of on site spoilages during wet weather.

Transportation

The total number of trips to building sites can be reduced. This is a growing importance because as more house building takes place on ‘brown field’ site in inner city area little detailed analysis has been conducted to date on transport benefits, but they are likely to vary considerably depending on the distance between the building site and the factory.

Public Attitude

A survey of MMC manufactures identified lack of market demand and public perception as the main two important limitations on expansion.

In the 2001 MORI poll, 69% of the respondent felt a brick built home would fetch a better piece. The negative attitude towards MMC may stem from the high publicised problem within historical use of pre fabricated housing. There are concerns that if more innovative MMC is used exclusively the distinction in design may mean residents are stigmatised.

Planning

The planning system has direct interest on the MMC market because of its role in determining the supply of land to house building. The government planning policy has laid down rules in planning policy guidance however the use of MMC is not currently mentioned and planning guidance would not generally cover such details about construction type.

Building Regulations

The U.K building regulations do not specify the building materials or the methods to be used but instead sets minimum performance standards. Proposed changes to the building regulations covering integrity are forthcoming. These changes may make it cheaper and easier for MMC to meet the regulation compared to the traditional masonry construction.

Health Safety

The construction industry has been considered the most dangerous for workers. In the U.K about 100 construction workers die a year. MMC would improve safety because there is a reduced risk of accidents in a controlled factory environment and less time spent on the construction site. The health and safety executive that regulate construction safety are encouraging the use of MMC.

Beco Wallform

This is a monolithic, insulated concrete system of building which is quick to construct yet offer level f performance significantly better than available form slower more traditional approach to building.

It is based on hollow light weight block components that lock together without intermediate bedding materials to provide a formwork system into which concrete is poured.

On set, the concrete becomes a high strength structure and the frame work remains in place as thermal insulation with U value ranging from0.30w/m2k to 0.12w/m2k.thus ideal for zero energy building. The building process is thus quick, tidy, and precise with low labour and equipment requirement than alternative methods.

Creative design is encouraged by the availability of a comprehensive range of components, which is enhanced by the build option to incorporate reinforcement for basement and multi story project.

Flexibility to the building due to the concrete makes it more practicable to coordinate other products and material system

It was developed in 1970s and it has been progressively improved and developed to satisfy the very best worldwide stranded of energy efficiency, and the recognised need for improved building techniques.

Forms Of MMC

Volumetric Construction

It involves three dimensional units produced in a factory, fully fitted out before being transported to site and stuck into prepared foundation to form the dwelling.

Volumetric construction is also known as modular construction. These units can be made from most materials including light gauge steel frame, timber frame, concrete and composites. The units are sometimes used alongside panels

Pods another type of volumetric unit usually asked for bathroom or similar high serviced areas. A volumetric construction is most efficient when used for large number of identical units an example would be in flats where a house is typically made up of four units plus roof.

Example of buildings with this mode of construction is the Summit house.

Panellised Construction

The flat panel units are build in a factory transported to the site for assembly into three dimensional structures or to fit within an existing structure. System includes wall, roof and floor and roof panels to create the complete structural shell. Factory made structure for and roof panels are known as cassettes.

The different types of panels include;

• Open panel; panel delivered to site where insulation window and services and lining are fitted. All structural components are visible. Panels can be structural or non structural closed as non load bearing separating walls and partitions.
• Closed panels; panel based on a structural framing system like the one used in open panel systems, it can have factory fitting windows, doors services, internal wall finishes and external cladding. The internal structure components can only be seen around the perimeter of the panel.
• Concrete panel; structural wall panel which can include cladding , insulation materials, windows and doors.
• Structural insulated panels; sand which construction comprising two year layers of sheet materials bounded to form insulation cover. They do not rely on internal studs for their structural performance. Used as wall and roof panels.
• In fill panels; non load bearing panel inserted within a structural frame. Any type of panel can be used although framed panels are more common.
• Curtain walling; vertical building enclosed system that support no load other than its own weight and the environmental load that acts upon it

Hybrid Construction

Volumetric units integrated with panelised system also referred to as semi volumetric construction. Highly serviced areas such as the kitchen and bathroom can be constructed as volumetric units with the rest of the dwelling constructed with panels.

Timber Frame Work

In timber frame construction of the internal frame work is wooden which has been designed to support the structure of the house. This frame is clad by facing materials such as brick or store to provide an alternative finish.

Concrete Forming

It is through the use of permanent insulated form work systems which provide a particular method of building insulated walls for houses.

Sub Assemblies And Components

These are large components that can be incorporated into either conventionally built or MMC dwelling.

These items are not full house system and are usually factory made or occasionally site assembled.

They include;

1. Pre fabricated foundation; a series of pre fabricated ground beams and other components assembled to form foundation quickly and accurately.
2. Floor cassettes; pre fabricated panel specifically designed for floor constructions. Fewer labour hours on site are needed per square metre of floor and reduce reduces work. It has health and safety benefits.
3. Roof cassettes; pre fabricated panels designed specifically for pitched roofs. The panel are very stiff and are designed to leave the loft free of struts and props, allowing easy production of room in the roof construction. Using the cassettes allows the building to become water tight and more quickly than conventional trussed rafter or cut roof construction.
4. Pre assembled roof structure; roof is assembled on ground level before constructing and shell off a dwelling. The roof can be craned into a place as soon as the rest of the super structure is in place, creating a weather tight structure more quickly.
5. Pre fabricated dormers; factory made dormer can speed the process by making the roof water tight.
6. Wining looms; cabling system manufactured so that they can be assemble quickly with relatively unskilled labourers. Cables are manufactured in various lengths and terminate with plug that simply plug into sockets and other electrical items.
7. Timber/ beams; light weight joints stood or rafters manufactured with solid and composite timber flanges with timber sheet material web to form a beam.
8. Metal web joint; light web joint comprising two timber flanges separated by light gauge steel lattice webs,

Energy Efficiency, Saving Money

The first step to taking a whole house energy efficient approach is to find out which part of the house uses the most energy. This will pinpoint those areas and suggest the most effective measures for cutting your energy costs;

TIPS

1. Check the insulation level in your attic exterior and basement walls, ceiling, floors, and crawl space.
2. Check for holes or cracks around the walls, ceiling, windows, doors, lights, and plumbing fixtures, the switches, electricity outlets that can leak air in or out of the house.
3. check for open fire place dumpers
4. Make sure that the appliances, heating and cooling systems are properly maintained. Read the owner manual for the recommended maintenance.
5. Study you families lighting need and use patterns paying special attention to high use areas such as the living room.

Formulating Your Plan

1. How much money do you intend to use.
2. where are your greatest energy loss
3. How long will it take for the investment of energy efficiency to pay for itself in energy cost saving.
4. Does your energy saving measure provide additional benefits that are important to you?
5. how long do you plan to own your current home
6. Can you do the job yourself or will you need to hire a contractor.

How To Use Less Fuel And Save Money

Light And Appliances

Energy saving bulbs is a good way of saving on energy because they can last up to ten times than the ordinary light bulbs. They work by using less electricity but give the same light output as other bulbs and their fore save on money.

When buying new appliances such as washing machines, tumble dryer of fridge ensure you find information on their energy efficiency by checking the energy level. ‘A’ related appliances are the most energy efficient and although these appliances may cost more will give in saving in both energy and cash.

Always wait until you have a full load before operating the washing machine and use a 40 degree most of the time to make a considerable savings.

Heating

If your house is centrally heated, you can make the heating efficient and less expensive by upgrading your heating controls. At times switch or programme allows you to set, heating and hot water to come on only at a time when needed. Use room thermostat which allows you to control each room temperature separately.

Avoid old boilers, which is one of the biggest causes of high fuel. All modern boiler systems are energy efficient and use less fuel to run. The most efficient boilers in terms of savings money are called considering boilers which use 30-40 less fuel.

Insulation

Insulation of the home can be away of reducing the amount of fuel used. Good insulation will keep the heat in the building and the cold out.

There are a number of cheap and measurers that can make your home dryer and wormer.

Example; if you home has wooden floors, you can fill gaps in floor boards and skirting with newspaper, beading or sealant and you can brush or seal to your outer doors.

The most effective way to insulate the house is to insulate the loft. Most houses have loft insulations but the energy saving will depend on how thick the insulation is. The recommended level of thickness for loft insulation is now a minimum of 100mm deep, but ideally should be between 150 and 200 mm. loft insulation should be allowed to retain its natural thickness and not be compressed this shall reduce the insulation level.

If the outside walls of the house are cavity walls, insulation can be added in the cavity. If your interior walls are solid, you can protect the exterior with render or cladding which is also weather proof. This work for purpose of safety should be carried out by a specialist.

Glazing

Double glazing stops heat form escaping and can reduce condensation on your window. A lot of heat is lost through the window so double glazing can be an effective way to make savings on fuel in the long term. It can reduce outside noise considerably. Glazing is quit expensive so it is important to consult before using it.

Secondary glazing is cheaper that replacement. Glazing can be bought from DIY shops. Savings are similar to those made by double glazing.

Getting The Best Price Fuel

Apart from general energy savings, fuel costs may be reduced by changing fuel providers. Many fuel companies know operate dual fuel schemes which can save your money if you buy both gas and electricity from their suppliers.

Sealing Air Leaks

Warm air leaking into the house during the summer and out during winter can cause a lot of money. One of the quickest saving tasks you can do is caulk and seal all cracks and opening of the outside.

Tips Of Sealing Air Leaks

1. Test your house for air tightness on a windy day, hold a little licences stick next to your window, door, electrical outlets, ceiling fixtures and other locations where there is a possible air path to the outside.
2. Caulk and weather strip door and windows that leak air.
3. Caulk and seal air leaks where plumbing, ducting, or electricity wiring penetrates through exterior walls, floors and ceiling.

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